weddingsite/app/api/login/route.ts

import { auth } from "@/auth/lucia";
import * as context from "next/headers";
import { NextResponse } from "next/server";
import { LuciaError } from "lucia";

import type { NextRequest } from "next/server";

export const POST = async (request: NextRequest) => {
	const formData = await request.formData();
	const username = formData.get("username");
	const password = formData.get("password");
	// basic check
	if (
		typeof username !== "string" ||
		username.length < 1 ||
		username.length > 31
	) {
		return NextResponse.json(
			{
				error: "Invalid username",
			},
			{
				status: 400,
			}
		);
	}
	if (
		typeof password !== "string" ||
		password.length < 1 ||
		password.length > 255
	) {
		return NextResponse.json(
			{
				error: "Invalid password",
			},
			{
				status: 400,
			}
		);
	}
	try {
		// find user by key
		// and validate password
		const key = await auth.useKey("username", username.toLowerCase(), password);
		const session = await auth.createSession({
			userId: key.userId,
			attributes: {},
		});
		const authRequest = auth.handleRequest(request.method, context);
		authRequest.setSession(session);
		return new Response(null, {
			status: 302,
			headers: {
				Location: "/", // redirect to profile page
			},
		});
	} catch (e) {
		if (
			e instanceof LuciaError &&
			(e.message === "AUTH_INVALID_KEY_ID" ||
				e.message === "AUTH_INVALID_PASSWORD")
		) {
			// user does not exist or invalid password
			return NextResponse.json(
				{
					error: "Incorrect username or password",
				},
				{
					status: 400,
				}
			);
		}
		return NextResponse.json(
			{
				error: "An unknown error occurred",
			},
			{
				status: 500,
			}
		);
	}
};